1. Field of the Invention
The present invention relates to a liquid jetting apparatus capable of appropriately jetting an image forming solvent on an image recording material such as a photosensitive material and an image receiving material, and an operation method of the liquid jetting apparatus.
2. Description of the Related Art
An image forming apparatus for conducting an image recording process by using two kinds of image recording materials, such as a photosensitive material and an image receiving material is known.
Inside this kind of image forming apparatus, an image forming solvent application section having a vessel for storing an image forming solvent to be applied to a photosensitive material is provided, and further, a heat developing transfer section comprising a heat drum and an endless press belt which rotates with the heat drum while pressing the outer periphery of the heat drum is provided.
The photosensitive material with the image exposed in the image forming apparatus while being held and conveyed is soaked in a vessel filled with water acting as the image forming solvent in the image forming solvent application section, then sent to the heat developing transfer section. At the same time, the image receiving material is also sent to the heat developing transfer section in the same way as the photosensitive material.
In the heat developing transfer section, the photosensitive material applied with water is superimposed with the image receiving material and wound closely around the outer periphery of the heat drum in this superimposed state. Further, both materials are held and conveyed between the heat drum and the endless press belt so that the photosensitive material is heat developed while the image is transferred onto the image receiving material. In this way, specified images can be formed (recorded) on the image receiving material.
However, since the photosensitive material is soaked in the vessel filled with water acting as the image forming solvent, water coming into contact with the photosensitive material is kept in the vessel at all times. As a result, bacteria in the vessel uses organic substances released from the photosensitive material in tiny amounts as a nutrition source and multiply. This fouls the water and increases the risk of deterioration of the image forming apparatus itself and image quality.
Therefore, an application method of jetting and spraying small water droplets from a jetting device filled with water on to the photosensitive material while vibrating a nozzle plate having nozzle holes without the water supply side, for example a vessel, coming into contact with the photosensitive material can be considered.
However, if bubbles enter the jetting device along with water from a water supply pipe when supplying water to the jetting device, the bubbles prevent stable jetting of water from the nozzle holes so as to disturb stable spraying, and thus homogeneous application of water onto a photosensitive material becomes difficult. Further, a risk is involved in that the water pressure may be applied excessively from the water pipe to the jetting device at the time of supplying water to the jetting device so that the water may accidentally leak from the nozzle holes.
Therefore, a method of carefully supplying water into the jetting device may be thought of, but, by supplying water carefully, the water supply time can increase and thus it is disadvantageous in that the waiting time before water jetting increases.
On the other hand, a water supply to the jetting device is required because water is lost during the spraying and jetting of water from the nozzle holes. However, if the water pressure is changed in the water supplied to the jetting device by the water supplied, the water jetting amount fluctuates and disturbs stable spraying, and thus is disadvantageous.
Furthermore, if water supplied into the jetting device contains a contaminant or a calcium component, which can generate scale, the nozzle holes of the jetting device can get choked and disturb stable jetting, and thus this too is disadvantageous.